Write the reaction equation: Al – Al2O3 – Al (NO3) 3 – Al (OH) 3 – Al2O3 – Na Al (OH) 4

1) Aluminum reacts with oxygen, we get – aluminum oxide:

4Al + 3O2 → 2Al2O3;

2) Aluminum oxide reacts with nitric acid resulting in aluminum nitrate and water:

Al2O3 + 6HNO3 → 2Al (NO3) 3 + 3H2O;

3) Aluminum nitrate enters into an exchange reaction with sodium hydroxide, in the process of such a reaction we get – aluminum hydroxide and sodium nitrate:

Al (NO3) 3 + 3NaOH → Al (OH) 3 ↓ + 3NaNO3;

4) Aluminum hydroxide, when heated, forms aluminum oxide and water:

2Al (OH) 3 → Al2O3 + 3H2O;

5) To obtain sodium tetrahydroxoaluminate, add sodium hydroxide and water to aluminum oxide:

Al2O3 + 2NaOH + 3H2O → 2Na [Al (OH) 4].